Method of metal electroplating

ABSTRACT

Electroplating a localized contact area on an electrically conductive portable member, such as a bus bar, cylindrical shafting or the like, while said member is removably resting in an electrically conductive but non-interengaged state on a current-carrying cathode bar that is electrically connected to a source of a plating current, and passing such plating current through said cathode bar to the member to be plated, while at the same time rubbing the contact area to be plated with a plating electrolyte-carrier to wet said area with the electrolyte and build up a plated layer thereon. The apparatus for use in carrying out the aforesaid method includes the movable cathode bar as an adjustable support affording not only a supporting, preferably edge contact, but also providing an inclinable surface for drainage thereover of electrolyte drippings into a sink or other receptacle.

United States Patent Primary Examiner-John H. Mack Assistant Examiner-T. Tufariello A ttorney -Ca r lton l lill, J. Arthur Gross et al.

Rapids July 17, 1973 METHOD OF METAL ELECTROPLATING [57] ABSTRACT 75 lnvemor; m Rapids, Chicago L Electroplating a localized contact area on an electrically conductive portable member, such as a bus bar,

[73] Assign: lf Electroplaflng Process, -a cylindrical shafting or the like, while said member is re- Chlcago, movably resting in an electrically conductive but non- [22] Fil d; Sept 9 197 interengaged state on a current-carrying cathode bar that is electrically connected to a source of a plating [2]] Appl' 1782907 current, and passing such plating current through said cathode bar to the member to be plated, while at the 52 us. c1. 204/15, 204/224 Same time rubbing the Contact area to he Plated with 511 Int. Cl C23b 5/48, 823p 1/02 a Plating electrolyte-Carrier said with [58] Field of Search 204/224, 15 electrolyte and build up a Plated layer thereoh- The paratus for use in carrying out the aforesaid method in- 5 References Cited cludes the movable cathode bar as an adjustable sup- FOREIGN PATENTS OR APPLICATIONS port affording not only a supporting, preferably edge contact, but also providing an mclmable surface for 13%;???) $1132; E2222I:I:3:::31:::::::::::::::::::::: 232253 drainage a Sink 505,273 8/1937 Great Britain 204/224 other receptacle 3 Claims, 3 Drawing Figures minnow 7W5 sum 1 or 2 v INVENTOR.

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SHEET 2 0F 2 v INVENTOR. F54 K. FflP/DS MW @WATTORNEYS METHOD OF METAL ELECTROPLATING RELATED INVENTIONS This is related to the invention disclosed'and claimed in my pending application Ser. No. 2,982, filed Jan. 15, 1970, and now abandoned, but does not stand in the category of an improvement of the invention of said pending application.

DESCRIPTION OF THE PRIOR ART Some of the features of my present invention are disclosed in the prior art, of which the patent to Hesse No. 2,244,620, dated June 3, 1941, is perhaps representa- SUMMARY OF THE INVENTION The present invention provides a method of electroplating a localized contact area on an electrically conductive portable member, which may be a bus bar, shaft, valve assembly, or the like that can be more-easily electroplated before being installed in a more or less permanent, stationary type of assembly. The method includes removably resting the portable member to be plated, sometimes referred to as a work piece, in an electrically conductive but non-interengaged state on a current-carrying cathode bar connected to a source of an unidirectional plating current. Electrical contact between the work piece and the support can be due solely to the contact established by 'the force of gravity, or gravity can be assisted by forces manually applied by the operator.

With contact established and the plating circuit closed that includes the work piece, the area of the work piece to be plated is rubbed, preferably manually, by means of a plating electrolyte-carrier so as to wet said area with the electrolyte while said area is serving as the cathode for receiving the metal'that is to be electrodeposited thereon.

Apparatus for carrying out the method of electroplating just described includes the movable, currentcarrying cathode bar connected to a source of a .plating current. The construction and arrangement of the apparatus is such that during theapplication of the plating electrolyte to the surface of the work piece to be plated, such surface can be positioned above an empty sink or pan, for collecting any drippings, either directly therein or by drainage of such drippings over .an inclined surface of the cathode bar into the sink. The apparatus requires no fixed tank, as such, for the electrolyte. Consequently the apparatus is considered tank less."

It is therefore an object of this invention to provide a simple and easily carried out method, using relatively simple and easily available equipment, for building up electrodeposits on localized areasof large equipment, such as punch presses, or on movable work pieces, or parts, either in their finally assembled state or in a preassernbled state.

Other and further objects of this invention will :become apparent from the following description of certain preferred embodiments taken in conjunction with the accompanying drawing and variations and modifications thereof and therein may be effected'without departing from the spirit and scope of the novel concepts of the disclosure, in which:

FIG. 1 of the drawing illustrates a preferred embodiment of my invention in the form of apparatus suitable for carrying out my method;

FIG. 2 is a modified form of apparatus for application of the method of my invention to building up an electrodeposit on a length of shafting or the like; and

FIG. 3 is a further modification of my invention as applied to a transverse surface of a cylindrical ported valve part.

As shown on FIG. 1 of the drawing, apparatus embodying my invention can be used with a table or other support 10 for a sink 113 for catching drippings from the use of an electrolyte in building up an electrodeposit of metal on a work piece, such as that generally indicated 'by the reference numeral 11. Said work piece 11 may take the form of a long bus bar that is manually movable prior to its assembly in a stationary relationship associated with electrical equipment. The bus bar 11 is positioned with its free end 12 extending above the sink 13 for drainage of electrolyte drippings thereinto. A wide mouth jar 15 for containing an electrolyte, indicated by the reference numeral 14, is supported in a trough 10a carried by the table 10. A surface area '16 at the free end 12 of said bus bar '1 1 represents the contact area that is to be built up by an electrodeposit of a 'suitable'metal such as copper, brass, nickel or the like.

The bus bar 11 rests upon a plating-current-carrying support 17, 'hereintermed a cathode bar which, as

shown, rests upon a bench 18, or other support adja cent an end 19 thereof. The cathode bar 17 is movably positioned on the bench 18 and releasably connected electrically by means of a connector 20 from a contact 21to a source of unidirectional current, indicated generallyby the symbol C, which may include a battery or a generator, and which is provided with a terminal 22 for electrical connection through the connector 20 to the cathode bar 17.

The cathode bar '17 is preferably formed of an electrical conductive '(-E.C.) grade of aluminum, since this :particular grade of aluminum does not become corroded or otherwise fouled up" during use in practicing the method of my invention. Therefore, the use of E. C. grade of aluminum ensures non-contamination of the .tanklessfplating solutions that are collected as a re'sultof'drippage in a=pan orother container for re-use, since tankless plating solutions do not attack E. C. grade aluminum.

Another contact post 23, connected to the source of plating current C, is connected by a flexible connector 25 to a manually movable electrolyte-applicator 26. Said applicator 26 is preferably provided with a holder 27 from which extends a fabric encased, relatively flat and narrow electrode 28. The fabric, indicated by the reference numeral 29,can be formed of any natural or synthetic textile that is relatively inert to the plating electrolyte and that is porous or otherwise permeable to or absorptive of said electrolyte and capable of re taining the electrolyte in the interstices provided by the woven or unwoven strands of the encasing fabric.

As a preliminary to electroplating the area 16, said area should bethoroughly cleaned so as to be receptive of the plating electrolyte. Cleaning can be effected in any customary and effective manner, with or without the use of anodicor cathodic cleaning steps. A faucet F is provided for washing or rinsing off the area 16 with water or other cleansing liquid. The sink 13 has an outlet that includes a perforated strainer 100.

With the bus bar 11 positioned on the cathode bar 17, was to have gravity contact of the under surface of the bus bar witha surface such as the free edge 30 of the cathode bar 17, the plating circuit on one side includes the post 22 and conductor 20, the contact connection between the conductive bus bar 11 and the edge 30 of the conductor support 17, and through the bus bar 11 to the area 16 to be plated; and, on the other side, through the contact post 23, the flexible conducting wire 25 to the electrolyte carried by the applicator 26 and through the electrolyte thereon to the surface area 16 to be plated. With the circuit energized, the operator manipulates the applicator 26 by rubbing the electrolyte-carrying surface of the applicator over the surface area 16, thereby insuring good contact and a substantially uniform build-up of electrodeposited metal onto said surface 16. The combined rubbing and plating operation is continued with the circuit energized until an optimum thickness and area of the electrodeposited metal has been achieved. During the electroplating operation any excess of electrolyte that may drip from the applicator 26 will drip into the sink or other receptacle l3 and be collected therein.

In the operation just described, the plating circuit is completed by the manual manipulation, first, of the bus bar 11 to make a gravity contact with the cathode bar 17, or with a free edge 30 thereof, and, secondly, through the rubbing contact that is manually controlled by relative movement between the fabric-encased applicator 26 and the area 16 that is to be plated. The cathode bar can be tilted into the position shown in FIG. 1 in dotted lines so that any drippage onto its upper surface will drain into the sink 13. The portability of the work piece '11 and the various components, including the cathode bar 17, facilitates the building up of the contact electroplate over the area 16 at or near the locus of the more or less stationary assembly for which the bus bar is intended. The-bus bar is merely illustrative of the work piece for which my method and apparatus are particularly suited.

In order to prevent displacement plating of the work piece 11, the operator should initiate the electrodeposition of silver on the bus bar near the lower edge 12 thereof and build up such electrodeposition upwardly of said edge and over the entire contact area 16. By following this procedure, the operator avoids displacement plating and its attendant poor adherence to the under-lying surface of the work piece.

In FIG. 2, a length of tubular or cylindrical shafting 35 constitutes the work piece, and an annular area 36 thereof illustrates the surface area that is to be built up by the electrodeposition thereon of the desired contact metal. A cathode bar 37, similar to the cathode bar 17, rests against a stationary supporting surface 38 near a free edge 39 thereof positioned adjacent a receptacle 40 for catching drippings and rinsings. The upper surface of the cathode bar 37 can be sloped toward the receptacle 40 to cause drainage of any electrolyte drippings thereover into said receptacle. The work piece 35 may either rest by gravity alone on the upper surface of the cathode bar 37, or it may be held manually thereagainst while rotating the work piece 35 about its axis with the area 36 in rubbing contact with a manually held applicator 41. The applicator 41 is electrically connected, as by means of a wire 42, to one side of an electric plating circuit, and the other side of said circuit is connected by means of a wire 43 and a post 44 to the conductive supporting member 37.

The electroplating operation is otherwise similar to that already described, but in the case of a cylindrical work piece, such as the shafting 35, the relative rubbing movement may be carried out by manually rolling the shaft 35 and holding the applicator 41 stationary and imparting a reciprocating movement to the applicator to produce a rubbing action between the surface of the area 36 to be plated and the contacting surface of the applicator 41.

In FIG. 3, the work piece is a ported valve part '45, or other similar relatively large diameter part having a transverse planar end face 46 for receiving the electrodeposition of metal by the method of my invention. As illustrated, an applicator 47 of suitable form and shape is held by hand against the surface 46 while the electroplating circuit is closed through a cathode bar 48 against which the work piece 45 rests or is manually held while being rolled along the upper surface thereof. As before, the cathode bar 48 is connected through a wire 50 to one side of an electroplating circuit, while the other side is connected through a post 51 and wire 52 to the applicator 47. Electroplating of the end surface 46 is continued until the desired thickness of electroplate has been built up thereon.

The embodiments of my invention as illustrated in the drawings all include a cathode bar that is manually positionable upon a non-conductive upper surface of a base, with electrical contact between the work piece and the cathode bar either due solely to the gravity contact that is established therebetween or by the gravity contact as assisted by the operator. This arrangement facilitates the electroplating of component parts of a more or less stationary assembly at or near the point of assembly but while in a disassembled condition. By making both the applicator of my invention portable and the work piece also portable or at least accessibleto the applicator, the entire operation of building up an electrodeposit of suitable metal on the work piece is greatly facilitated.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

- 1. In a method of electroplating a localized contact area on a portable electrically conductive workpiece wherein a current is passed through a liquid electrolyte absorptively carried on a rubbing surface of an applicator and the electrolyte is applied to said contact area while effecting relative rubbing movement between said surface and said contact area, the improvement which comprises providing said applicator with a handle and an elongated flat rubbing surface extending therefrom, establishing an electroplating circuit including said electrolyte and said contact area through the medium of a manually movable cathode member in said circuit to complete said circuit and to effect electoplating of said contact area, adjusting said cathode member into inclined, supporting and electrically conductive contact relative to said workpiece for receiving any of said drippings and rinsings for drainage into said collector while making said contact area freely accessible throughout its full extent to said applicator to plate said contact area during said relative rubbing movement between said surface and said contact area, and

adjusting said cathode member relative to said contact area so that during such plating said contact area is in an elevated position above a collector for drippings and rinsings falling from said contact area.

2. The method as defined by claim 1, wherein said workpiece is cylindrical in shape and is manually rolled electrically conductive contact therebetween. 

2. The method as defined by claim 1, wherein said workpiece is cylindrical in shape and is manually rolled in contact with said cathode during effecting plating of said contact area.
 3. The method of claim 1, wherein said workpiece is manually pressed against said cathod member to insure electrically conductive contact therebetween. 